Electrodes for physiological signal recognition

Abstract

Electrodes that can be used to determine a first type of physiological signal and a second type of physiological signal are disclosed. The first type of physiological signal can be electromyography (EMG) signals produced by activity of muscles and tendons. Identification of hand movements can be supplemented with pose detection circuitry such as inertial measurement units (IMUs). These EMG signals can be processed to identify hand movements and recognize gestures associated with those hand movements. The second type of physiological signal can be electromyography (ECG) signals produced by the heart. The electrodes can be used to detect EMG and ECG signals dependent upon a current configuration of sensing circuitry. The electrodes can be used to determine a measurement quality associated with the EMG signals.

1 . A wearable electronic device comprising:
 a plurality of electrodes;   sensing circuitry;   pose detection circuitry, different from the sensing circuitry; and   one or more processors, wherein the one or more processors are configured to:
 in a first mode of operation:
 configure the plurality of electrodes and the sensing circuitry in a first configuration to detect first physiological signals corresponding to a first type of physiological measurement using the plurality of electrodes and using the pose detection circuitry; and 
 
 in a second mode of operation,
 configure the plurality of electrodes and the sensing circuitry in a second configuration to detect second physiological signals corresponding to a second type of physiological measurement, different from the first type of physiological measurement, using the plurality of electrodes. 
 
   
     
     
         2 . The wearable electronic device of  claim 1 , wherein the first type of physiological measurement is an electromyogram. 
     
     
         3 . The wearable electronic device of  claim 1 , wherein the second type of physiological measurement is an electrocardiogram. 
     
     
         4 . The wearable electronic device of  claim 1 , wherein the pose detection circuitry includes one or more inertial measurement units. 
     
     
         5 . The wearable electronic device of  claim 1 , further comprising:
 switching circuitry; and   a plurality of amplifiers including a first amplifier and a second amplifier, wherein:
 in the first mode of operation, a first pair of the plurality of electrodes are differentially coupled to the first amplifier via the switching circuitry, and 
 in the second mode of operation, a second pair of the plurality of electrodes, different from the first pair of the plurality of electrodes, are differentially coupled to the second amplifier via the switching circuitry. 
   
     
     
         6 . The wearable electronic device of  claim 5 , wherein the sensing circuitry includes one or more analog-to-digital converters coupled to outputs of the first amplifier and the second amplifier. 
     
     
         7 . The wearable electronic device of  claim 1 , wherein the one or more processors are further configured to:
 during the first mode of operation, use one or more machine learning models to detect a movement of a portion of a body of a user wearing the wearable electronic device.   
     
     
         8 . The wearable electronic device of  claim 7 , wherein the portion of the body of the user includes a hand of the user wearing the wearable electronic device, and using the one or more machine learning models to detect the movement of the portion of the body of the user includes determining a predicted gesture corresponding to movement of the hand. 
     
     
         9 . The wearable electronic device of  claim 1 , wherein the one or more processors are further configured to:
 during the first mode of operation, use one or more machine learning models to detect a pose of a portion of a body of a user wearing the wearable electronic device.   
     
     
         10 . The wearable electronic device of  claim 8 , wherein the portion of the body of the user includes a hand of the user wearing the wearable electronic device, and using the one or more machine learning models to detect the pose of the portion of the body of the user includes determining a predicted pose of the hand. 
     
     
         11 . The wearable electronic device of  claim 1 , further comprising:
 stimulation circuitry couplable to one of the plurality of electrodes and the sensing circuitry for injecting a test signal into the sensing circuitry,   wherein the one or more processors are further configured to:
 determine a quality of the first physiological signals from the sensing circuitry based on the injected test signal, and 
 in accordance with a determination that the quality of the first physiological signals satisfy one or more criteria:
 detect a movement of a portion of a body of a user wearing the wearable electronic device using the first physiological signals and using the pose detection circuitry, and 
 
 in accordance with a determination that the quality of the first physiological signals does not satisfy the one or more criteria, detect the movement of the portion of the user's body using the pose detection circuitry, forgoing use of the first physiological signals to detect the movement. 
   
     
     
         12 . The wearable electronic device of  claim 11 , wherein the one or more criteria include a criterion that is satisfied when a conductance between a first electrode of the plurality of electrodes and a second electrode of the plurality of electrodes is greater than a threshold level of conductance. 
     
     
         13 . The wearable electronic device of  claim 11 , wherein the one or more criteria include a criterion that is satisfied when a level of noise associated with the first physiological signals is greater than a threshold level of noise. 
     
     
         14 . The wearable electronic device of  claim 1 , further comprising:
 stimulation circuitry couplable to one of the plurality of electrodes and the sensing circuitry for injecting a test signal into the sensing circuitry,   wherein the one or more processors are further configured to:
 determine a quality of the first physiological signals from the sensing circuitry based on the injected test signal, and 
 in accordance with a determination that the quality of the first physiological signals satisfy one or more criteria:
 detect a pose of a portion of a body of a user wearing the wearable electronic device using the first physiological signals and using the pose detection circuitry, and 
 
 in accordance with a determination that the quality of the first physiological signals does not satisfy the one or more criteria, detect the pose of the portion of the user's body using the pose detection circuitry, forgoing use of the first physiological signals to detect the pose. 
   
     
     
         15 . A non-transitory computer readable medium storing instructions, wherein the one or instructions are configured to cause one or more processors included in a wearable electronic device further including a plurality of electrodes, sensing circuitry, and pose detection circuitry, different from the sensing circuitry, to:
 in a first mode of operation:
 configure the plurality of electrodes and the sensing circuitry in a first configuration to detect first physiological signals corresponding to a first type of physiological measurement using the plurality of electrodes and using the pose detection circuitry; and 
   in a second mode of operation:
 configure the plurality of electrodes and the sensing circuitry in a second configuration to detect second physiological signals corresponding to a second type of physiological measurement, different from the first type of physiological measurement, using the plurality of electrodes. 
   
     
     
         16 . A method of operating a wearable electronic device comprising a plurality of electrodes, sensing circuitry, and pose detection circuitry, different from the sensing circuitry, the method comprising:
 in a first mode of operation:
 configuring the plurality of electrodes and the sensing circuitry in a first configuration to detect first physiological signals corresponding to a first type of physiological measurement using the plurality of electrodes and using the pose detection circuitry; and 
   in a second mode of operation:
 configuring the plurality of electrodes and the sensing circuitry in a second configuration to detect second physiological signals corresponding to a second type of physiological measurement, different from the first type of physiological measurement, using the plurality of electrodes. 
   
     
     
         17 . The non-transitory computer readable medium storing instructions of  claim 15 , wherein the first type of physiological measurement is an electromyogram. 
     
     
         18 . The non-transitory computer readable medium storing instructions of  claim 15 , wherein the second type of physiological measurement is an electrocardiogram. 
     
     
         19 . The method of  claim 16 , wherein the first type of physiological measurement is an electromyogram. 
     
     
         20 . The method of  claim 16 , wherein the second type of physiological measurement is an electrocardiogram.